Aspectos clínicos y forenses del color rosa de los dientes: reporte de un caso / Clinical and forensic aspects of the pink color of teeth: report of a case

La coloración rosa de los dientes puede originarse por diferentes factores. En el ámbito forense se ha descrito al fenómeno denominado post mortem pink teeth como un signo asociado a muertes violentas de etiología diversa. En la práctica clínica también es posible observar pacientes con dientes rosados, fre-cuentemente ocasionados por traumatismos o iatro-genia proveniente de ortodoncia, cuyo mecanismo de producción obedece a distintas etiopatogenias, destacándose las reabsorciones dentinarias inter-nas, cemento-dentinarias externas y calcificaciones dentinarias. El presente artículo expone el caso de un individuo adulto con antecedente de trauma óseo-dentario por accidente vial que, luego de un prolon-gado tiempo, asiste al Servicio de Urgencias Odon-tológicas y Orientación de Pacientes de la Facultad de Odontología de la Universidad de Buenos Aires, en donde se le detecta, a modo de hallazgo exploratorio, una ostensible coloración rosada en el canino infe-rior derecho. La situación motivó un pormenorizado abordaje clínico y radiográfico, indagando respecto a los probables factores que intervinieron en su ge-neración y desarrollo (AU)

The pink coloration of the teeth can be caused by dif-ferent factors. In the forensic field, the phenomenon called post mortem pink teeth has been described as a sign associated with violent deaths of various etiology. In clinical practice, it is also possible to ob-serve patients with pink teeth, frequently caused by trauma or iatrogenesis from orthodontics, whose production mechanism is due to different etiopatho-genesis, highlighting internal dentin resorption, ex-ternal cemento-dentinal resorption and dentin calci-fications. This article presents the case of an adult individual with a history of bone-dental trauma due to a road accident who, after a long time, attends the Dental Emergency and Patient Guidance Service of the Faculty of Dentistry of the University of Bue-nos Aires, where an ostensible pink coloration was detected in the lower right canine as an exploratory finding. The situation motivated a detailed clinical and radiographic approach, inquiring about the probable factors that intervened in its generation and development (AU)

Evaluación del estatus del tejido pulpar postratamiento oncológico / Assessment of the status of the pulp tissue post oncological treatment

La OMS cataloga al cáncer como uno de los principales problemas en el ámbito mundial, los pacientes sometidos a terapia oncológica son más vulnerables a desarrollar complicaciones en los tejidos de la cavidad bucal entre las que tenemos: mucositis, infecciones, osteorradionecrosis. En el manejo endodóntico hay que tomar en consideración que los trata- mientos como yodoterapia, radioterapia y quimioterapia pueden generar efectos sobre el complejo dentinopulpar. El objetivo de este artículo es determinar el estatus del tejido pulpar postratamiento oncológico mediante la revisión sistemática en bases de datos de gran relevancia científica, como PubMed, Scielo, Medigraphic, Science direct. Se concluye que el sistema estomatognático es un receptor importante de estos efectos y secuelas en pacientes con terapia oncológica, el tejido pulpar no está libre de estas secuelas ya que genera daño celular, como la hipovascularidad, hipocelularidad e hipoxia la cual incrementa el riesgo de necrosis de la región (AU)

The WHO lists cancer as one of the main problems worldwide, patients undergoing oncological therapy are more vulnerable to developing complications in the tissues of the oral cavity among which we have: mucositis, infections, osteoradionecrosis. In endodontic management, it should be taken into consideration that treatments such as iodine therapy, radiotherapy, and chemotherapy can generate effects on the dentin-pulp complex. This article aims to determine the status of the pulp tissue after oncologic treatment. Through a systematic review in databases of great scientific relevance, such as PubMed, Scielo, Medigrafhic, Science direct. It is concluded that the stomatognathic system is an important receptor of these effects and sequelae in patients with oncological therapy, the pulp tissue is not free of these sequelae as it generates cellular damage because of the hypo vascularity, hypocellularity, and hypoxia which increases the risk of necrosis of the region (AU)

Urgência em Endodontia: diagnóstico e tratamento em casos de pulpite irreversível sintomática / Urgency in Endodontics: Diagnosis and Treatment in Cases of Symptomatic Irreversible Pulpitis

Objetivo: discutir sobre o diagnóstico e a conduta terapêutica em casos de urgência endodôntica em dentes que apresentam pulpite irreversível sintomática. Material e Métodos: realizou-se uma revisão bibliográfica de estudos publicados nos últimos 5 anos (2015- 2020) por meio de busca nas bases de dados: PubMED, BVS (Biblioteca Virtual em Saúde) e Scielo (Scientific Eletronic Library). Para a pesquisa, foram utilizados os seguintes descritores: Pulpite Irreversível (Irreversible Pulpitis), Tratamento (Treatment), Dor (Pain) e Endodontia (Endodontics). Resultados: O diagnóstico é um passo fundamental no tratamento das urgências e emergências de origem endodôntica, pois é a partir do correto diagnóstico que será instituído o tratamento correto, reestabelecendo o conforto do paciente. Quando o profissional dispõe de tempo suficiente para realizar a remoção do tecido pulpar e o preparo do canal radicular, esse é o tratamento de escolha para os casos de pulpite irreversível sintomática, o qual pode ser realizado em sessão única ou em múltiplas sessões. Quando o profissional não dispõe de tempo suficiente para realizar o tratamento endodôntico convencional, a opção de tratamento é realizar apenas o atendimento de urgência para retirar o paciente do quadro de dor aguda presente, e em um momento futuro realizar o tratamento endodôntico completo. Conclusão: As urgências endodônticas sempre estão presentes nos consultórios odontológicos, os profissionais devem estar sempre preparados para realizar um correto diagnóstico e tratamento para cada caso, trazendo assim conforto ao paciente.

Objective: to discuss the diagnosis and therapeutic management in cases of endodontic urgency in teeth with symptomatic irreversible pulpitis. Material and Methods: a bibliographic review of studies published in the last 5 years (2015-2020) was carried out by searching the databases: PubMED, BVS (Virtual Health Library) and Scielo (Scientific Electronic Library). For the research, the following descriptors were used: Irreversible Pulpitis, Treatment, Pain and Endodontics. Results: The diagnosis is a fundamental step in the treatment of urgencies and emergencies of endodontic origin, as it is from the correct diagnosis that the correct treatment will be instituted, reestablishing the patient's comfort. When the professional has enough time to remove the pulp tissue and prepare the root canal, this is the treatment of choice for cases of symptomatic irreversible pulpitis, which can be performed in a single session or in multiple sessions. When the professional does not have enough time to carry out the conventional endodontic treatment, the treatment option is to perform only emergency care to remove the patient from the present acute pain condition, and at a future time to carry out the complete endodontic treatment. Conclusion: Endodontic emergencies are always present in dental offices, professionals must always be prepared to carry out a correct diagnosis and treatment for each case, thus bringing comfort to the patient.

Terapia endodóntica en pacientes adultos mayores ¿qué debemos tener en cuenta? / Endodontic therapy in elderly patients, what should we consider?

De acuerdo con la tendencia mundial, el número de personas de 60 años y más va en aumento. Este crecimiento demográfico de la población, el aumento de las expectativas de vida de las personas y la tendencia a la disminución de pacientes edéntulos, produce una mayor demanda de procedimientos endodónticos en la población anciana. Es fundamental que el odontólogo conozca la fisiología del envejecimiento para poder abordar, en forma eficaz, el tratamiento en los pacientes pertenecientes a este grupo etario. Se ha descripto que los tejidos dentales sufren cambios a lo largo de la vida; entre ellos, la reducción del número de fibroblastos, de odontoblastos, de vasos sanguíneos y de fibras nerviosas; el aumento de fibras colágenas, de masas calcificadas, aposición de cemento, de dentina secundaria y de dentina de reparación. El objetivo del presente trabajo es realizar una revisión bibliográfica en relación a los cambios que presentan la pulpa dental, la dentina y el cemento, relacionados con el proceso de envejecimiento y sus posibles dificultades al momento de realizar el tratamiento endodóntico; sin olvidar cómo pueden inferir en el éxito del tratamiento las posibles patologías sistémicas que presentan los pacientes a consecuencia de la edad (AU)

According to the world trend, the number of people aged 60 and over is increasing. This demographic growth of the population, the increase in people's life expectancies and the tendency to decrease edentulous patients, produces a greater demand for endodontic procedures in the elderly population. It is essential that the dentist knows the physiology of aging to be able to effectively address the treatment in patients belonging to this age group. It has been described that dental tissues suffer changes throughout life, including the reduction of the number of fibroblasts, odontoblasts, blood vessels and nerve fibers; the increase of collagen fibers, calcified masses, apposition of cement, secondary dentin and repair dentin. The objective of the present work is to carry out a bibliographic review in relation to the changes that the dental pulp, dentine and cement have in relation to the aging process and its possible consequences in the endodontic treatment; without forgetting how it can infer in the success of the treatment the possible systemic pathologies that patients present as a result of age (AU)

Expression of factors involved in dental pulp physiopathological processes by nemotic human pulpal fibroblasts.

AIM: To investigate in human dental pulp fibroblasts (HDPF) the expression of factors involved in dental pulp physiopathological processes and in an experimental model of cell activation called nemosis, and to compare the behaviour of pulp cell activation with sound lung fibroblast MRC5, employed as a reference model for nemosis. METHODOLOGY: Nemotic response was induced in three-dimensional cultures of HDPF and lung fibroblasts. The expressions of molecules involved in physiological (alkaline phosphatase, type I collagen) and in inflammatory processes (IL-6, CXCL8, CCL20, COX-2) were studied using real-time PCR. Concentrations of IL-6 and CXCL8 were analysed during 4 days with ELISA. Nonparametric tests were used to determine statistical differences between groups. RESULTS: A significant decrease (P < 0.001) in type I collagen and alkaline phosphatase was observed in MRC5 and HDPF nemotic responses. Although the amounts of mRNA differed between these cell types, there was an increase in CCL20, CXCL8 and COX-2 expression (P < 0.001). Unlike HDPF, MRC5 spheroids displayed significant amounts of IL-6 concentrations and mRNA expression. Notably, increased concentrations of CXCL8 were recorded in all three-dimensional cultures compared with monolayers as a function of time (P < 0.05). CONCLUSION: Although the nemotic responses observed were not identical in the pulpal and lung fibroblasts, similarities occurred in the expression of chemokines and cyclooxygenase-2. Nemotic reactions and inflammatory processes in pulp diseases share similarities in terms of the expression of factors. Thus, this in vitro model could constitute a powerful tool to study intercellular relations within the dental pulp and to develop new local treatments to counteract the inflammatory reaction that occurs during pulpitis.

Age-related morphological, histological and functional changes in teeth.

Throughout lifetime, the teeth are continuously exposed to numerous chemical and physical impacts, which cause the wear of the dental hard tissues, gingival recession and other oral changes with sometimes subsequent problems. Age-related wear of tooth surfaces reduces the dental enamel thickness and exposes deeper layers of enamel, which have different physical and chemical properties than the surface enamel. Gingival recession is the main causal factor of root caries and dentine hypersensitivity. Age-related changes in dentine include the formation of secondary dentine and the reduction in tubular lumen diameter (dentine sclerosis), which lead to a reduction in the volume of the pulp chamber. In addition to the reduction in the volume of pulp chamber, changes to the dental pulp also include dental pulp calcifications. The age-related physiological changes to the teeth should be carefully distinguished from pathological changes, especially when they induce pain or a negative impact on the oral health-related quality of life (OHRQoL) of the older individuals. Therefore, regular oral examinations coupled with early preventive measures should aim at maintaining oral health until old age.

Disruption of kif3a results in defective osteoblastic differentiation in dental mesenchymal stem/precursor cells via the Wnt signaling pathway.

The anterograde intraflagellar transport motor protein, kif3a, regulates the integrity of primary cilia and various cellular functions, however, the role of kif3a in dental mesenchymal stem/precursor cell differentiation remains to be fully elucidated. In the present study, the expression of kif3a was knocked down in human dental follicle cells (hDFCs) and human dental pulp cells (hDPCs) using short hairpin RNA. The results of subsequent immunofluorescence revealed that knocking down kif3a resulted in the loss of primary cilia, which led to impairment of substantial mineralization and expression of the differentiation­associated markers, including alkaline phosphatase, Runt­related transcription factor 2, dentin matrix protein 1 and dentin sialophosphoprotein in the hDFCs and hDPCs. The results of reverse transcription­quantitative polymerase chain reaction and western blot analyses showed that the expression levels of Wnt3a­mediated active ß­catenin and lymphoid enhancer­binding factor 1 were attenuated, whereas the expression of phosphorylated glycogen synthase kinase 3ß was enhanced, in the kif3a­knockdown cells. In addition, exogenous Wnt3a partially rescued osteoblastic differentiation in the hDFCs and hDPCs. These results demonstrated that inhibition of kif3a in the hDFCs and hDPCs disrupted primary cilia formation and/or function, and indicated that kif3a is important in the differentiation of hDFCs and hDPCs through the Wnt pathway. These findings not only enhance current understanding of tooth development and diseases of tooth mineralization, but also indicate possible strategies to regulate mineralization during tooth repair and regeneration.

DPSCs from Inflamed Pulp Modulate Macrophage Function via the TNF-α/IDO Axis.

Human dental pulp stem cells (DPSCs) can be isolated from inflamed pulp derived from carious teeth with symptomatic irreversible pulpitis (I-DPSCs), which possess stemness and multidifferentiation potentials similar to DPSCs from healthy pulp. Since macrophages-essential cell players of the pulpal innate immunity-can regulate pulpal inflammation and repair, the authors investigated the immunomodulatory effects of DPSCs/I-DPSCs on macrophage functions and their underlying mechanisms. Similar to DPSCs, I-DPSCs were capable of colony-forming efficiency and adipogenic and osteo/dentinogenic differentiation under in vitro induction conditions. I-DPSCs also expressed a similar phenotypic profile of mesenchymal stem cell markers, except a relatively higher level of CD146 as compared with DPSCs. Coculture of DPSCs or I-DPSCs with differentiated THP-1 cells, the human monocyte cell line, markedly suppressed tumor necrosis factor α (TNF-α) secretion in response to stimulation with lipopolysaccharides (LPS) and/or nigericin. However, unlike TNF-α, the secreted level of interleukin 1ß was not affected by coculture with DPSCs or I-DPSCs. Furthermore, DPSC/I-DPSC-mediated inhibition of TNF-α secretion by macrophages was abolished by pretreatment with 1-methyl-D-tryptophan, a specific inhibitor of indoleamine-pyrrole 2,3-dioxygenase (IDO), but not by NSC-398, a specific inhibitor of COX-2, suggesting IDO as a mediator. Interestingly, IDO expression was significantly augmented in macrophages and mesenchymal stromal cells in inflamed human pulp tissues. Collectively, these findings show that I-DPSCs, similar to DPSCs, possess stem cell properties and suppress macrophage functions via the TNF-α/IDO axis, thereby providing a physiologically relevant context for their innate immunomodulatory activity in the dental pulp and their capability for pulp repair.

Life cycles of traumatized teeth: long-term observations from a cohort of dental trauma victims.

Life cycles of dental trauma victims can provide important clinical information, especially when viewed over many years. In this first series of life cycles, the pulp and periodontal responses to traumatic injuries of four patients are documented over periods varying from 26 to 51 years. The dynamics of pulp survival following an intrusive luxation and two avulsions are followed, with particular reference to pulp canal calcification to which a new term, root canal stenosis, has been proposed. The life cycles include the successful management of inflammatory root resorption in a replanted tooth with an open apex contrasting with the early prophylactic endodontic treatment of two replanted teeth in a patient with mature apices. The long-term development of invasive cervical resorption in one of the patient's life cycle highlights the importance of ongoing follow-up examinations for dental trauma victims.

Tissue characterization following revascularization of immature dog teeth using different disinfection pastes

Abstract Revascularization of immature teeth with necrotic pulps traditionally involves the use of triple antibiotic paste, which may sometimes lead to undesirable complications. The objective of this study was to assess tissue repair in immature dog teeth with apical periodontitis subjected to revascularization, comparing two different pastes used for root canal disinfection. Apical periodontitis was induced in 30 dog premolars. Teeth were randomly divided into three experimental groups: root canals filled with triple antibiotic paste (n = 10); root canals filled with 1% propolis paste (n = 10); and no medication (n = 10). An additional group (n = 10, no intervention) was used as control. After 7 months, the jaws were histologically evaluated for the following variables: newly formed mineralized tissue (present/absent); vital tissue in the canal space (absent/periodontal ligament-like/pulp-like); apical extension of root (present/absent); and severity of inflammatory process (absent/mild/moderate/severe). There were no statistically significant differences among the experimental groups in new mineralized tissue formation and apical root development. The formation of vital tissue in the canal space, in turn, was statistically different between the triple paste and propolis groups: vital tissues were present in all revascularized teeth disinfected with propolis paste (100%), compared to 71% of those disinfected with the triple paste. Severity of inflammatory process was different between the triple paste and no medication groups. The new tissues formed onto canal walls and in the root canal space showed characteristics of cementum and periodontal ligament, respectively. Propolis may have some advantages over the triple paste for the revascularization of immature teeth.

Temporal dynamics of anxiety phenotypes in a dental pulp injury model.

BACKGROUND: Accumulating clinical and preclinical evidence indicates that chronic pain is often comorbid with persistent low mood and anxiety. However, the mechanisms underlying pain-induced anxiety, such as its causality, temporal progression, and relevant neural networks are poorly understood, impeding the development of efficacious therapeutic approaches. RESULTS: Here, we have identified the sequential emergence of anxiety phenotypes in mice subjected to dental pulp injury (DPI), a prototypical model of orofacial pain that correlates with human toothache. Compared with sham controls, mice subjected to DPI by mechanically exposing the pulp to the oral environment exhibited significant signs of anxiogenic effects, specifically, altered behaviors on the elevated plus maze (EPM), novelty-suppressed feeding (NSF) tests at 1 but not 3 days after the surgery. Notably, at 7 and 14 days, the DPI mice again avoided the open arm, center area, and novelty environment in the EPM, open field, and NSF tests, respectively. In particular, DPI-induced social phobia and increased repetitive grooming did not occur until 14 days after surgery, suggesting that DPI-induced social anxiety requires a long time. Moreover, oral administration of an anti-inflammatory drug, ibuprofen, or an analgesic agent, ProTx-II, which is a selective inhibitor of NaV1.7 sodium channels, both significantly alleviated DPI-induced avoidance in mice. Finally, to investigate the underlying central mechanisms, we pharmacologically blocked a popular form of synaptic plasticity with a GluA2-derived peptide, long-term depression, as that treatment significantly prevented the development of anxiety phenotype upon DPI. CONCLUSIONS: Together, these results suggest a temporally progressive causal relationship between orofacial pain and anxiety, calling for more in-depth mechanistic studies on concomitant pain and anxiety disorders.

Stem Cell Transplantation for Pulpal Regeneration: A Systematic Review.

For treating pulpal pathological conditions, pulpal regeneration through transplanted stem/progenitor cells might be an alternative to conventional root canal treatment. A number of animal studies demonstrated beneficial effects of stem/progenitor cell transplantation for pulp-dentin complex regeneration, that is, pulpal tissue, neural, vascular, and dentinal regeneration. We systematically reviewed animal studies investigating stem/progenitor cell-mediated pulp-dentin complex regeneration. Studies quantitatively comparing pulp-dentin complex regeneration after transplantation of stem/progenitor cells versus no stem/progenitor cell transplantation controls in intraoral in vivo teeth animal models were analyzed. The following outcomes were investigated: regenerated pulp area per root canal total area, capillaries per total surface, regenerated dentinal area per total defect area, and nerves per total surface. PubMed and EMBASE were screened for studies published until July 2014. Cross-referencing and hand searching were used to identify further articles. Standardized mean differences (SMD) and 95% confidence intervals (95% CI) were calculated using random-effects meta-analysis. To assess possible bias, SYRCLE's risk of bias tool for animal studies was used. From 1364 screened articles, five studies (representing 64 animals) were included in the quantitative analysis. Risk of bias of all studies was high. Stem/progenitor cell-transplanted pulps showed significantly larger regenerated pulp area per root canal total area (SMD [95% CI]: 2.28 [0.35-4.21]) and regenerated dentin area per root canal total area (SMD: 6.91 [5.39-8.43]) compared with no stem/progenitor cell transplantation controls. Only one study reported on capillaries per or nerves per total surface and found both significantly increased in stem/progenitor cell-transplanted pulps compared with controls. Stem/progenitor cell transplantation seems to enhance pulp-dentin complex regeneration in animal models. Due to limited data quantity and quality, current evidence levels are insufficient for further conclusions.

Effect of conditioned medium from preameloblasts on regenerative cellular differentiation of the immature teeth with necrotic pulp and apical periodontitis.

INTRODUCTION: The purpose of this study was to investigate the effect of conditioned medium (CM) from murine preameloblasts on the cellular differentiation of mesenchymal stem cells (MSCs) in immature teeth with necrotic pulp and apical periodontitis. METHODS: Pulp necrosis and apical periodontitis were induced in 30 immature permanent double-rooted premolars of 3 beagles and were randomly assigned to the following treatment groups: group CM (n = 10), revascularization treatment was performed using CM from preameloblasts of C57BL/6 mice apical bud cells; group CR (n = 10), conventional revascularization treatment was performed; positive control group (n = 5), left infected; and negative control group (n = 5), untreated. The dogs were followed up for 12 weeks and assessed for treatment outcomes with radiographic and histologic analyses. The effect of the CM on sequential Runx2 and osterix messenger RNA gene expression during the differentiation of MG63 osteoblastlike cells was analyzed with real-time polymerase chain reaction. RESULTS: The overall treatment outcomes were not significantly different between the 2 treatment groups. However, the teeth in the CM group showed significantly more mature apices and a higher degree of hard tissue formation with projections intercalating into the pre-existing root dentin (P < .05). In CM-treated teeth, regenerated pulplike tissue was more frequently observed (P < .05). During differentiation, the CM induced early peak expression of Runx2 followed by sustained osterix overexpression. CONCLUSIONS: CM from preameloblasts rendered a favorable effect in providing a physiologic microenvironment for the differentiation of MSCs after revascularization treatment.

Chronic tooth pulp inflammation induces persistent expression of phosphorylated ERK (pERK) and phosphorylated p38 (pp38) in trigeminal subnucleus caudalis.

BACKGROUND: Extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase are transiently phosphorylated (activated) in the spinal cord and trigeminal nucleus by acute noxious stimuli. Acute stimulation of dental pulp induces short-lived ERK activation in trigeminal subnucleus caudalis (Vc), and p38 inhibition attenuates short-term sensitization in Vc induced by acute pulpal stimulation. We have developed a model to study central changes following chronic inflammation of dental pulp that induces long-term sensitization. Here, we examine the effects of chronic inflammation and acute stimulation on the expression of phosphorylated ERK (pERK), phosphorylated p38 (pp38) and Fos in Vc. RESULTS: Chronic inflammation alone induced bilateral expression of pERK and pp38 in Vc, but did not induce Fos expression. Stimulation of both non-inflamed and inflamed pulps significantly increased pERK and pp38 bilaterally; expression was greatest in inflamed, stimulated animals, and was similar following 10-min and 60-min stimulation. Stimulation for 60 min, but not 10 min, induced Fos in ipsilateral Vc; Fos expression was significantly greater in inflamed, stimulated animals. pERK was present in both neurons and astrocytes; pp38 was present in neurons and other non-neuronal, non-astrocytic cell types. CONCLUSIONS: This study provides the first demonstration that chronic inflammation of tooth pulp induces persistent bilateral activation of ERK and p38 within Vc, and that this activation is further increased by acute stimulation. This altered activity in intracellular signaling is likely to be linked to the sensitization that is seen in our animal model and in patients with pulpitis. Our data indicate that pERK and pp38 are more accurate markers of central change than Fos expression. In our model, localization of pERK and pp38 within specific cell types differs from that seen following acute stimulation. This may indicate specific roles for different cell types in the induction and maintenance of pulpitic and other types of pain.

Aging of in vitro pulp illustrates change of inflammation and dentinogenesis.

INTRODUCTION: Dental pulp functions include pulp cell activity involvement in dentin formation. In this study we investigated the age-related changes in dental pulp cells that may influence pulp cell activity for restoring pulp function. METHODS: Human dental pulp cells (HDPCs) were serially subcultured until spontaneously arrested. Altered expression of chronic inflammatory molecules and age-related molecules were determined by Western blotting. Odontogenic functions impaired by senescence were assayed by Western blotting, reverse transcriptase polymerase chain reaction, alkaline phosphatase activity, and alizarin red S staining. To understand the mechanism of aging process by stress-induced premature senescence (SIPS), the cells were treated with H(2)O(2). Replicative senescence and SIPS were also compared. RESULTS: Replicative senescence of HDPCs was characterized by senescence-associated ß-galactosidase activity and reactive oxygen species formation. These cells exhibited altered expression of chronic inflammatory molecules such as intracellular adhesion molecule-1, vascular cell adhesion molecule-1, peroxisome proliferator activated receptor-gamma, and heme oxygenase-1 and age-related molecules such as p53, p21, phosphorylated-extracellular signal-regulated kinase, and c-myb. SIPS cell results were similar to replicative senescence. Furthermore, HDPCs decreased odontogenic markers such as dentin sialophosphoprotein and dentin matrix-1 and osteogenic markers such as bone morphogenetic protein-2 and -7, runt-related transcription factor-2, osteopontin, alkaline phosphatase activity, and mineralized nodule formation by replicative senescence and SIPS. CONCLUSIONS: This study suggests that development of aging-related molecules in pulp cells offers understanding of cellular mechanisms and biological events responsible for tooth preservation and maintenance strategies for healthy teeth across the life span.

Pulpal and periradicular response to caries: current management and regenerative options.

The pulp-dentin complex is a strategic and dynamic barrier to various insults that plague the dentition. Researchers have yet to understand the complete potential of this shifting junction and its components. The most common cause of injury to the pulp-dentin complex is carious breakdown of enamel and dentin. In recent years, there has been a change in restorative management of caries. The emphasis is on strategies to preserve dentin and protect the pulp. This article provides a brief review of the effect of caries on the pulp, of subsequent events on the periradicular tissues, and of current understanding of treatment modalities.

Regenerative endodontics: barriers and strategies for clinical translation.

Regenerative endodontics has encountered substantial challenges toward clinical translation. The adoption by the American Dental Association of evoked pulp bleeding in immature permanent teeth is an important step for regenerative endodontics. However, there is no regenerative therapy for most endodontic diseases. Simple recapitulation of cell therapy and tissue engineering strategies that are under development for other organ systems has not led to clinical translation in regeneration endodontics. Recent work using novel biomaterial scaffolds and growth factors that orchestrate the homing of host endogenous cells represents a departure from traditional cell transplantation approaches and may accelerate clinical translation.

Root resorption of primary molars without successor teeth. An experimental study in the beagle dog.

Tooth agenesis is a common craniofacial congenital malformation in humans, but little is known about the mechanisms of root resorption in this condition. The purpose of this study was to investigate the mechanisms of root resorption in primary molars without successors. An animal model without permanent tooth germs was established by surgery in beagles. The times of onset of primary molar root resorption, with and without successors, were compared. The distribution of immune cells, odontoclasts, and their activating factors were determined by histochemistry and immunohistochemistry. Root resorption of primary mandibular molars without successors began later than physiological resorption. In primary molars without permanent germs, odontoclasts and immune cells were present mainly in the apical pulp at the start of root resorption, whereas in control teeth receptor activator of nuclear factor-κB ligand (RANKL)-positive cells were found mainly in the region of the periodontal ligament. CD14(+) and CD3(+) cells were found in both the pulp and the periodontal ligament region. These results suggest that the dental pulp of primary molars, as well as immune cells, may play an important role in root resorption in primary molars without permanent tooth germs.

Effects of changes in vertical occlusal dimension on heart rate fluctuations in guinea pigs.

BACKGROUND: We have previously reported that the decrease of the vertical occlusal dimension (VOD) led to heart failure and abnormalities in creatine phosphokinase (CPK) in guinea pigs. In the present study, we investigated the autonomic activity and the origin of the abnormality in CPK under different occlusal conditions. MATERIALS AND METHODS: Guinea pigs were separated into the following five groups: untreated control, reduced VOD, slit, restored VOD and increased VOD groups and compared for their electrocardiogram and heart rate fluctuations for two weeks using Fluclet, computer software. RESULTS: The control group revealed no changes in heart rate fluctuations or posture. The reduced VOD group exhibited a two-phase wave of heart rate fluctuations, with the first peak 0-2 days after teeth grinding, and the second peak starting from 4 days after teeth grinding until sudden death (usually 12th day), accompanied by head drop. The slit and the restored VOD groups exhibited only the first peak. The increased VOD group, with approximately 3 mm-thick acrylic pellets bonded to the posterior teeth, showed no heart rate fluctuations. Body weight loss was most prominent in the reduced VOD group, and became much milder in the order of increased VOD, restored and slit groups. The reduced VOD group exhibited transient elevation of skeletal muscle type of CPK isozyme activity within two days after treatment. CONCLUSION: The present study suggests that the first peak of heart rate fluctuations is caused by pulpal stimulation, and the second peak by excessive contraction (excessive excitation of the motor output system and the autonomic nervous system) of the masticatory muscles. On the other hand, increased VOD did not influence either the motor or the autonomic nervous system.

Study on the histopathological modifications of the dental pulp in occlusal trauma.

The diagnosis of occlusion-generated disorders of the dento-maxillary apparatus represents a sensitive stage within the establishment of the therapeutic means for the functional rehabilitation of dental arches. The laborious effort carried out in order to specify the diagnosis resides in the fact that any trauma arising at the level of any component of the stomatognate system may lead to an occlusal dysfunction. The uncured carious processes, besides the pulp and periapical complications, may lead to an occlusal dysfunction through horizontal migrations of teeth resulting in the derangement of the occlusal curvatures as well as through vertical migrations of the teeth opposing a tooth diagnosed with occlusal caries or which largely reduced the coronary height. The dental iatrogenia, besides the eructation anomalies and neuromuscular dysfunction within the oromaxillofacial area also determines the appearance of occlusal dysfunction. The radiological examination through correlation with the clinical manifestations may provide significant data related to the magnitude of the prejudice caused to dento-paradontal units experiencing occlusal trauma. The histopathological study through correlation with the clinical manifestations provides significant data on the tolerance of dento-paradontal units within the occlusal dysfunction. Also, subsequent to the analysis of the possible actions of aggression generated by the occlusal trauma correlations could be determined between the type of the histological lesion of the pulp-dentine complex and the etiopathogenic factors, as well as correlations depending on the damage degree through occlusal trauma of the dental parts involved.